If anti-malware apps get going like they should, such a kill switch is unnecessary except for, I guess, rights management. And not just to things like media, but (perhaps more importantly?) rights of ownership to platform. Connectivity seems to be changing notions of ownership... or perhaps we can say the ease with which products escape the original owners rights to exclusive economic exploitation now is necessitating new notions of ownership by calling for and being the source of creation of new tools to express ownership... kill switches, for instance. People like Google might maintain kill switches with a view to maintaining the integrity of their "free" product, and thus maintaining their competitive advantage. People haven't seemed to ask why it is Google sponsors Android, and that's curious because Google is huge and Android is free. Supposedly Android acts as a moat. It's free, thus spectacularly difficult for, say, Microsoft to compete on a price basis when supplying operating systems to phone manufacturing companies, thus more phones will come out with Android, thus fewer opportunities exist for people other than Google to provide search services... but what protects Android itself? Kill switches.
Okay, a bit of a stretch. If this were in the BS lounge I could go further.
I wonder if there's apps that'll block kill switch commands. If there were a market for such things, it wouldn't be the Android Market... or would it?